The fresh computed tool usage of explosives develops towards raise out-of material firmnessadmin
Approach centered on direct lithology shipments
In the process of stone blasting, new physical and mechanized functions of your rock try seriously that of your head items you to definitely dictate the result off stone blasting 21 . There was tend to an obscure with the knowledge that the new more challenging new stone, the brand new more complicated it’s are blasted in today’s technologies business. But not, the latest blasting feeling isn’t just as requested within the technology means. As an alternative, it is often discovered that the fresh stiffness off material isn’t high once the device consumption of explosives are high 22 .
According to the cracking device out of material blasting 23 , the power released by explosives serves towards rocks of the treat trend and extension stress off detonation gas whenever a volatile explodes to the rocks. The best exhaustion out-of rocks is because of the action worry produced by the fresh new explosion exceeding their strength restrict, and that demonstrates that new crushing county is actually directly linked to new rush time as well as the physical characteristics of the stone. Put simply, beneath the particular conditions regarding tool explosive practices form, sort of, and 100 % free epidermis, the fresh charges quantity is mainly influenced by the fresh new mechanical attributes away from material to attain a particular smashing impact. Ergo, the new lithology shipping is regarded as the primary reason behind deciding the brand new product usage of explosives twenty-four .
From inside the a call at-breadth study of the lithology away from hard rock, it’s unearthed that higher fret has a life threatening influence on the new blasting process and you may material breaking perception. The outcomes also demonstrate that high-webpages fret handling and you will blasting packing aren’t two separate process, to the contrary, they work into the collaboration, additionally the active unloading features a significant impression twenty five . For this reason, the new shipping away from hard rock is the key into the construction away from a good segmented costs getting blasthole.
Collection away from blasthole stone strata
Regarding the conventional blasting processes, new lithology change along the great time gap breadth isn’t sensed regarding the blasting build. Therefore, a single charges structure was used. Regarding the superimposed material mass having delicate and difficult inclusions, brand new weak interlayer’s compressing and you can tensile opposition fuel have become reduced compared with one to from the complex material formations, almost negligible. During the time, brand new weak interlayer can quickly get to be the overflow channel of the detonation gas and you can deteriorate brand new crushing and you may putting effect of the latest high-tension fuel made by this new burst. As well, regarding highest hard rock instead of explosion cracks, it is challenging to crack significant rocks using the supplementary smashing concept off cut-off stone accident throughout the throwing techniques due to help you a weak interlayer twenty-six . Therefore, brand new division out-of soft-rock and hard rock is a vital action on the framework strategy.
The lithology data of the corresponding blastholes are obtained by intelligent drilling rigs. According to the hardness of the lithology, the blasthole rock strata are divided into 7 categories, and lithology classification numbers range from Type 1 to Type 7 27 . In order to facilitate the design and calculation of blasthole charge structure, the adjacent strata with similar lithology are combined and grouped. The lithology is divided into two groups of soft rock and hard rock, denoted as \(s\) and \(h\) , respectively. The classification rule of soft rock and hard rock is that the strata numbered 1, 2, 3, and 4 are soft rocks, and rock strata numbered 5, 6, and 7 are hard rocks. The grouping diagram of blasthole rock strata is shown in Fig. 4: H refers to the blasthole depth, Rs means the thickness of soft rock, and Rh means the thickness of hard rock.